Learn More
A new method for PID controller tuning based on process models for cascaded control systems is proposed in this paper. The method consists of first finding the ideal controller that gives the desired closed loop response and then finding the PID approximation of the ideal controller by Maclaurin series. This method can be applied to any open loop stable(More)
Reactive oxygen species (ROS) have been implicated in the pathogenesis of a number of neurodegenerative disorders. However, the underlying mechanism of ROS-induced cell injury remains to be defined. This study was undertaken to examine the role of lipid peroxidation and poly (ADP-ribose) polymerase (PARP) activation in H2O2-induced cell death in A172 cells,(More)
The present study was undertaken to examine the role of reactive oxygen species (ROS) and glutathione (GSH) in glia cells using human glioma cell line A172 cells. HgCl2 caused the loss of cell viability in a dose-dependent manner. HgCl2-induced loss of cell viability was not affected by H2O2 scavengers catalase and pyruvate, a superoxide scavenger(More)
Proportional, integral, and deriuatiue (PID) parameters are obtained for general process models by approximating the feedback form of an IMC controller with a Maclaurin series in the Laplace uariable. These PID parameters yield closed-loop responses that are closer to the desired responses than those obtained by PID controllers tuned by other methods. The(More)
As the technology scales, the increase of circuit delay over time due to NBTI (negative bias temperature instability) effect is not negligible any more. It has been known that voltage scaling is an effective scheme that is able to mitigate the NBTI effect. However, a careful control of voltage scaling is required not to increase the dissipation of dynamic(More)
Power gating in circuits is one of the effective technologies to allow low leakage and high performance operations. This work aims to <i>analyze and establish the relations between the three important design parameters in power gated circuits: (i) the maximum current flowing from/to power/ground (ii) the wakeup (sleep to active mode transition) time delay(More)
Very long instruction word processors (VLIW) allow to execute multiple instructions in parallel. At the same time VLIW compilers optimize the source code for maximum performance by grouping as many instructions in parallel as possible. This work addresses the problem of thermal- awareness in VLIW compilers with a temperature control and reduction techniques(More)
The interaction of chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor CXCR4 may play an important role in the regulation of anterior pituitary function. In this study, we investigated the expression of CXCL12 and CXCR4 and their role in normal rat pituitary and GH-producing GH3 tumor cell line. RT-PCR analysis and immunohistochemistry revealed that(More)
The prevalence of Behcet's disease is the highest in the East Asian and the Mediterranean countries. Behcet's disease is also distributed in the Asian countries, but the nationwide survey has not been performed in Korea yet. The Korean Study Group for Behcet's Disease, founded in 1999, conducted a multicenter, retrospective survey on epidemiologic and(More)