Fractional order integrator for the relay feedback identification of a process Nyquist point in the third quadrant

A fractional order integrator can be used for the relay feedback identification of a process Nyquist point in the third quadrant, and to implement the fractional order integrator, it is often approximated by integer order systems. Here, instead of the usual rational transfer function approximation of the fractional order integrator in the relay feedback system, a simple analytic method which utilizes the on-off characteristics of relay output is proposed. Simulation results show that the proposed method can find process Nyquist points in the third quadrant without worrying about the approximation errors and ranges of the fraction order integrator.     

Efficient Iris Recognition through Improvement of Feature Vector and Classifier

In this paper, we propose an efficient method for personal identification by analyzing iris patterns that have a high level of stability and distinctiveness. To improve the efficiency and accuracy of the proposed system, we present a new approach to making a feature vector compact and efficient by using wavelet transform, and two straightforward but efficient mechanisms for a competitive learning method such as a weight vector initialization and the winner selection. With all of these novel mechanisms, the experimental results showed that the proposed system could be used for personal identification in an efficient and effective manner.     

Aloe barbadensis extracts reduce the production of interleukin-10 after exposure to ultraviolet radiation

Cutaneous exposure to ultraviolet radiation suppresses the induction of T cell mediated responses such as contact and delayed type hypersensitivity (DTH) by altering the function of immune cells in the skin and causing the release of immunoregulatory cytokines. Extracts of crude Aloe barbadensis gel prevent this photosuppression. Because the regulation of contact hypersensitivity and DTH responses differ, we investigated whether protection was afforded by a single or multiple agents in Aloe and the mechanism by which this material prevents suppression of DTH immunity. The ability of Aloe gel to prevent suppression of contact hypersensitivity responses to hapten decayed rapidly after manufacture. In contrast, agents that protected against systemic suppression of DTH responses to Candida albicans were stable over time. Oligosaccharides prepared from purified Aloe polysaccharide prevented suppression of DTH responses in vivo and reduced the amount of IL-10 observed in ultraviolet irradiated murine epidermis. To assess the effect of Aloe extracts on keratinocytes, Pam 212 cells were exposed in vitro to ultraviolet radiation and treated for 1 h with Aloe oligosaccharides. Culture supernatants were collected 24 h later and injected into mice. Supernatants from ultraviolet irradiated keratinocytes suppressed the induction of DTH responses, whereas Aloe oligosaccharide treatment reduced IL-10 and blocked the suppressive activity of the supernatants. These results indicate that Aloe contains multiple immunoprotective factors and that Aloe oligosaccharides may prevent ultraviolet induced suppression of DTH by reducing keratinocyte derived immunosuppressive cytokines.     

Negative‐Tone Block Copolymer Lithography by In Situ Surface Chemical Modification

Negative‐tone block copolymer (BCP) lithography based on in situ surface chemical modification is introduced as a highly efficient, versatile self‐assembled nanopatterning. BCP blends films consisting of end‐functionalized low molecular weight poly(styrene‐ran‐methyl methacrylate) and polystyrene‐block‐Poly(methyl methacylate) can produce surface vertical BCP nanodomains on various substrates without prior surface chemical treatment. Simple oxygen plasma treatment is employed to activate surface functional group formation at various substrates, where the end‐functionalized polymers can be covalently bonded during the thermal annealing of BCP thin films. The covalently bonded brush layer mediates neutral interfacial condition for vertical BCP nanodomain alignment. This straightforward approach for high aspect ratio, vertical self‐assembled nanodomain formation facilitates single step, site‐specific BCP nanopatterning widely useful for various substrates. Moreover, this approach is compatible with directed self‐assembly approaches to produce device oriented laterally ordered nanopatterns.     

Realizations of parallel and multibit-parallel shift registergenerators

We consider how to realize parallel shift register generators (PSRG) and multibit PSRGs, which can be directly used for parallel frame synchronous scrambling (FSS) in the bit- and multibit-interleaved multiplexing environments. We first describe the structure of PSRGs in terms of three parameters-the state transition matrix, the initial state vector, and the generating vectors. Then we discuss how to determine the three parameters of PSRGs that generate the desired parallel sequences in general. We further develop a method for the realization of minimum length PSRGs, and for the realization of PSRGs with minimized circuit complexity. Finally, we consider how to realize minimal PSRGs for use in multibit-parallel scrambling. The results are summarized in four sets of theorems, and are demonstrated through four examples     

Third quadrant Nyquist point for the relay feedback autotuning of PI controllers

The original relay feedback autotuning method of Astrom and Hagglund [1] is based on the Nyquist point at the phase angle of −π (the critical frequency). Recently, Friman and Waller [8] showed that the critical frequency is too high to tune PI controllers and proposed an autotuning method that finds a Nyquist point at the third quadrant through the two-channel relay. Here, the method to find Nyquist points in the third quadrant is revisited and adaptive relay feedback method which can be applied to noisy processes is proposed. It is shown that the bandwidths of PI control systems and the first-order plus time delay model identifications support the Nyquist point at the third quadrant. Nyquist points at the third quadrant can be obtained by introducing a filter and hysteresis to the relay feedback loop. However, the filter time constant and the size of hysteresis should be adjusted iteratively because their phase shifts are dependent on the resulting relay oscillation frequency. Simulations show that this adaptive relay feedback method finds a given Nyquist point at the third quadrant accurately under noisy environments and provides excellent PI control systems.