Distributed Supervisory Control of Discrete-Event Systems with Communication Delay

This paper identifies a property of delay-robustness in distributed supervisory control of discrete-event systems (DES) with communication delays. In previous work a distributed supervisory control problem has been investigated on the assumption that inter-agent communications take place with negligible delay. From an applications viewpoint it is desirable to relax this constraint and identify communicating distributed controllers which are delay-robust, namely logically equivalent to their delay-free counterparts. For this we introduce inter-agent channels modeled as 2-state automata, compute the overall system behavior, and present an effective computational test for delay-robustness. From the test it typically results that the given delay-free distributed control is delay-robust with respect to certain communicated events, but not for all, thus distinguishing events which are not delay-critical from those that are. The approach is illustrated by a workcell model with three communicating agents

Effects of Thioglycolic Acid on Parthenogenetic Activation of Xenopus Oocytes

BACKGROUND: Existing in Permanent-wave solutions (PWS), thioglycolic acid (TGA) is widely used in hairdressing industry for its contribution to hair styling. However, the toxicity of TGA, especially its reproductive toxicity, gradually calls the attention of more and more researchers. METHOD: In this work, xenopus oocytes were pretreated with different concentration of TGA, and then activated by calcium ionophore A23187. During culture, the oocytes activation rates were taken note at different time after adding calcium ionophore A23187. At the end of the culture period, the nuclear status was detected under confocal microscope. In addition, some other samples were collected for Western-Blotting analysis. RESULT: TGA significantly inhibited the oocytes activation rate and pronuclear formation. It may be resulted from the inhibition of the degradation of p-ERK1, Mos and CyclinB2. CONCLUSION: TGA inhibits in vitro parthenogenetic activation of xenopus oocytes with inhibited the degradation of proteins involved in mitogenic-activated protein kinase (MAPK) and maturation-promoting factor (MPF) pathways

Rare and low-frequency coding variants alter human adult height

Height is a highly heritable, classic polygenic trait with ~700 common associated variants identified so far through genome - wide association studies . Here , we report 83 height - associated coding variants with lower minor allele frequenc ies ( range of 0.1 - 4.8% ) and effects of up to 2 16 cm /allele ( e.g. in IHH , STC2 , AR and CRISPLD2 ) , >10 times the average effect of common variants . In functional follow - up studies, rare height - increasing alleles of STC2 (+1 - 2 cm/allele) compromise d proteolytic inhibition of PAPP - A and increased cleavage of IGFBP - 4 in vitro , resulting in higher bioavailability of insulin - like growth factors . The se 83 height - associated variants overlap genes mutated in monogenic growth disorders and highlight new biological candidates ( e.g. ADAMTS3, IL11RA, NOX4 ) and pathways ( e.g . proteoglycan/ glycosaminoglycan synthesis ) involved in growth . Our results demonstrate that sufficiently large sample sizes can uncover rare and low - frequency variants of moderate to large effect associated with polygenic human phenotypes , and that these variants implicate relevant genes and pathways

Effects of different concentrations of dimethylsulfoxide on development of zebrafish embryos and dopamine neurons

bjective To study the effect of exposures to different concentrations of dimethyl sulfoxide (DMSO) on the development of zebrafish embryos and dopaminergic (DA) neurons. Methods Tg(Vmat2 :GFP) zebrafish embryos of the same generation were randomized into 10 groups at 6 h post-fertilization for exposures to 9 concentrations (0.1%, 0.3%, 0.5%, 0.8%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0%; V/V) of DMSO for 72 h or without any exposure (blank control group). The survival rate, deformity rate, hatching rate and behavioral changes of the embryos were analyzed. The development of DA neurons was observed using laser confocal microscopy, and the cell proliferation and apoptosis were detected using PH3 antibody and an apoptosis detection kit, respectively. Results Exposure to 2.5% DMSO significantly decreased the survival rate of the zebrafish embryos (P < 0.01); at the concentration of 2.0%, DMSO exposure caused an obvious increase in the malformation rate (P < 0.01) and a decrease in the hatching rate of the embryos (P < 0.05); DMSO at 2.5% significantly decreased the frequency of tail swing of the zebrafish embryos (P < 0.05). Zebrafish embryos exposed to 0.5% DMSO showed a significantly reduced number of DA neurons (P < 0.05). Exposure of the zebrafish embryos to DMSO at a concentration above 0.3% significantly reduced the proliferation of the diencephalon cells (P < 0.01), and a DMSO concentration above 0.8% could obviously increase apoptosis of the dopaminergic neurons. Conclusion DMSO exposure causes developmental disorders in zebrafish embryos, and its neurotoxicity can result in loss of dopaminergic neurons in the diencephalon and suppress the cell proliferation

Delay-Robustness in Distributed Control of Timed Discrete-Event Systems Based on Supervisor Localization

Recently, we studied communication delay in distributed control of untimed discrete-event systems based on supervisor localisation. We proposed a property called delay-robustness: the overall system behaviour controlled by distributed controllers with communication delay is logically equivalent to its delay-free counterpart. In this paper, we extend our previous work to timed discrete-event systems, in which communication delays are counted by a special clock event tick. First, we propose a timed channel model and define timed delay-robustness; for the latter, a verification procedure is presented. Next, if the delay-robust property does not hold, we introduce bounded delay-robustness, and present an algorithm to compute the maximal delay bound (measured by number of ticks) for transmitting a channelled event. Finally, we demonstrate delay-robustness on the example of an under-load tap-changing transformer

Discrete element simulation of surface mechanical attrition treatment with rough-surface sonotrode

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Design and current balancing optimization of A 1700V/1000A multi-chip SiC power module

The rated current of a single SiC MOSFET is always less than 100A at a voltage rating higher than 1.2kV. Therefore, plenty of SiC MOSFET dies paralleled as multichip power modules to increase the current capacity. However, due to the asymmetric layout and the difference between chip parameters, there will be severe current imbalance in power modules, affecting the reliability. This paper presents a multi-chip 1700V/1000A SiC power module, consisting of 18 paralleled chips in each switch of the half-bridge topology. A serial of current balancing optimization method is proposed, including chip classification, the optimization of layout, power terminals and driver loop. Finally, the double pulse test (DPT) is conducted to verify the performance of the power module