Detecting sensor fault for nonlinear systems in T–S form under sampled-data measurement: Exact direct discrete-time design approach

A direct discrete-time design methodology for sampled-data sensor fault detection for nonlinear systems in Takagi–Sugenos form is proposed. Contrary to the conventional schemes in this way that rely on an approximate discrete-time model of the nonlinear system, our result is established based on an exact one. Condition to design the observer and the residual gain under an H-/H _∞ performance criterion is presented in matrix inequality format. An example is given to illustrate the effectiveness of the proposed methodology.     

Immediate post-reminder injection of gamma-amino butyric acid (GABA) agonist midazolam attenuates reactivation of forgotten fear in the infant rat.

J. H. Kim, G. McNally, and R. Richardson (2006) reported that pretest injection of FG7142, a GABA inverse agonist, alleviated infantile amnesia in rats. From this, it was concluded that GABAergic neurotransmission is involved in the forgetting seen in the developing rat. The present study extends that finding by examining the role of GABA in the reactivation of a forgotten memory in the infant rat. Sixteen-day-old rats were conditioned to fear a white noise. When tested 3 days later, rats that had not received a reminder treatment exhibited substantial forgetting. Reactivation of memory (as assessed by high levels of freezing) was observed in rats that were given a reminder shock and injected with saline the day before test. However, rats given a reminder shock and injected with midazolam immediately afterward failed to exhibit the reactivation effect. A subsequent experiment replicated this finding and further showed that midazolam did not reduce the memory reactivation effect when injected 2 hr after the reminder episode. From this, it appears that alterations in GABAergic neurotransmission may be an underlying process mediating memory reactivation in the infant rat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Weighted aggregation and fuzzy-concept-guided signal resemblance and expansion for video format conversion

In this paper, we propose an efficient deinterlacing method for HDTV that preserves image structures, edges, and details. In the human visual system, the eyes are more sensitive to high-frequency information such as edge details than low-frequency information such as image background. Therefore, averaging low-pass filter results is not effective for image enhancement. The proposed method is a weighted filtering approach that generates a half-pixel 9-by-9 edge-based line average window. We also propose pixel-resemblance- and pixel-expansion-based fuzzy weights, which are assigned using a triangular membership function. Compared to conventional format conversion methods, the proposed method outperforms all benchmarks in terms of both objective and subjective qualities.     

Antitumor Effect of Cycloastragenol in Colon Cancer Cells via p53 Activation

Colorectal cancer cell (CRC) is the fourth most common cancer in the world. There are several chemotherapy drugs available for its treatment, though they have side effects. Cycloastragenol (CY) is a compound from Astragalus membranaceus (Fisch.) Bge known to be effective in aging, anti-inflammatory, anticancer, and anti-heart failure treatments. Although many studies have demonstrated the functions of CY in cancer cells, no studies have shown the effects of p53 in colon cancer cells. In this study, we found that CY reduces the viability of colon cancer cells in p53 wild-type cells compared to p53 null cells and HT29. Furthermore, CY induces apoptosis by p53 activation in a dose- and time-dependent manner. And it was confirmed that it affects the L5 gene related to p53. Additionally, CY enhanced p53 expression compared to when either doxorubicin or 5-FU was used alone. Altogether, our findings suggest that CY induces apoptosis via p53 activation and inhibits the proliferation of colon cancer cells. In addition, apoptosis occurs in colon cancer cells due to other factors. Moreover, CY is expected to have a combined effect when used together with existing treatments for colon cancer in the future.     

Prediction of forced convective boiling heat transfer coefficient of pure refrigerants and binary refrigerant mixtures inside a horizontal tube

Forced convective boiling heat transfer coefficients were predicted for an annular flow inside a horizontal tube for pure refrigerants and nonazeotropic binary refrigerant mixtures. The heat transfer coefficients were calculated based on the turbulent temperature profile in liquid film and vapor core considering the composition difference in vapor and liquid phases, and the nonlinearity in mixing rules for the calculation of mixture properties. The heat transfer coefficients of pure refrigerants were estimated within a standard deviation of 14% compared with available experimental data. For nonazeotropic binary refrigerant mixtures, prediction of the heat transfer coefficients was made with a standard deviation of 18%. The heat transfer coefficients of refrigerant mixtures were lower than linearly interpolated values calculated from the heat transfer coefficients of pure refrigerants. This degradation was represented by several factors such as the difference between the liquid and the overall compositions, the conductivity ratio and the viscosity ratio of both components in refrigerant mixtures. The temperature change due to the concentration gradient was a major factor for the heat transfer degradation and the mass flux itself at the interface had a minor effect.     

Channel Estimation Scheme for WLAN Systems with Backward Compatibility

IEEE 802.11n standards introduced a mixed‐mode format frame structure to achieve higher throughput with multiple antennas while providing backward compatibility with legacy systems. Although multi‐input multi‐output channel estimation was possible only with high‐throughput long training fields (HT‐LTFs), the proposed scheme utilizes a legacy LTF as well as HT‐LTFs in a decision feedback manner to improve the accuracy of the estimates. It was verified through theoretical analysis and simulations that the proposed scheme effectively enhances the mean square error performance.     

Synthesis of Mg2FeH6 by hydrogenation of Mg/Fe powder mixture prepared by cold roll milling in air: Effects of microstructure and oxygen distribution

Herein, we describe the synthesis of Mg₂FeH₆ by hydrogenation of a 2.1 Mg:Fe (mol/mol) powder mixture prepared by cold roll milling (CRM) in air. The thickness of Fe layers and the amount and distribution of oxygen with number of CRM passes were systematically analyzed. CRM-induced microstructural changes were shown to play an important role in Mg₂FeH₆ formation. Although repeated CRM effectively decreased the Fe layer thickness to values sufficient for the fast formation of Mg₂FeH₆, too much CRM passes decreased the total degree of hydrogenation due to inevitable oxidation of Mg in air. Both microstructure refinement and minimal oxidation are the prerequisites for efficient Mg₂FeH₆ synthesis, with the former condition being achievable by optimizing the number of milling passes, and the latter one requiring CRM under an inert atmosphere.