Identification of delayed system using instrumental variable method

System identification uses system inputs and outputs to raise mathematical models.Various techniques of system identification exist that offer a nominal model and an uncertainty bound.Many practical systems such as thermal processes & chemical processes have inbuilt time delay.If the time delay used in the system model for controller design does not concur with the actual process time delay,a closed-loop system may be unstable or demonstrate unacceptable transient response characteristics so here the time delay is assumed to be time-invariant. This paper proposes on-line identification of delayed complex/uncertain systems using instrumental variable(Ⅳ) method.Parametric uncertainty has been considered which may be represented by variations of certain system parameters over some possible range.This method allows consistent estimation when the system parameters are associated with the noise terms,as the IV methods(IVM’s)usually make no assumption on the noise correlation configuration.The faster convergence of the parameters including noise terms has been proved in this paper.Iterative prefiltering(IP)method has also been used for the identification of the delayed uncertain system and the graphical results given in this paper demonstrate that the convergence results are inferior to the instrumental variable method.     

OPTIMIZATION OF GLUTEN PEAK TESTER: A STATISTICAL APPROACH

ABSTRACT

Response surface methodology was applied to develop a standard method for gluten peak tester. Four variables – flour weight, temperature, solvent and rpm – were varied as per the center composite design, and the responses – torque and peak maximum time – were analyzed. Flour–solvent interaction was observed to be the most significant factor impacting the peak torque for whole meal and hard wheat flours while flour (g) and rpm were the most significant for soft wheat flour and insignificant for whole meal flour. The setting 8.5 g flour, 9.5 g solvent (0.5 M CaCl₂), 34C temperature and 1,900 rpm was obtained as the standard setting applicable to whole meal as well as refined flours from soft and hard wheats.

PRACTICAL APPLICATIONS

Gluten quality is an important criterion to predict flour performance in cereal processing industry. The gluten peak tester has been recently introduced as a sensitive and rapid way of testing wheat gluten quality. The current research was designed to optimize the gluten peak tester to work with wheat varieties with a wide range of protein contents so as to lay a baseline for method development to assess gluten quality of different wheat varieties/lines within a short time span with minimum sample requirements which is very critical for the breeding industry.     

BLACK TIP DISCOLORATION IN INDIAN RICE. EFFECT OF EXTENDED MILLING ON MILLING CHARACTERISTICS, CHEMICAL COMPOSITION AND COOKING QUALITY

Extended milling of rice decreased the incidence of mycoflora and reduced black tip discoloration but reduced the head rice yield and kernel weight. Protein content, ash, reducing sugars, nonreducing sugars and free fatty acids increased whereas amylose decreased significantly with the increase in the number of discolored grains. Discolored rice required significantly less time to cook, showed decreased water uptake, reduced kernel elongation and losses. Cooking time decreased; water uptake, elongation in cooked rice and gruel solid loss increased with an increase in the degree of milling. Correlation coefficients between the different variables were calculated.     

A RESEARCH NOTE CHEMICAL CHANGES IN HELIANTHUS ANNUUS AND EUCALYPTUS LANCEOLATUS HONEY DURING STORAGE

A comparison between changes in hydroxymethylfurfural, pH, total acidity and free acids content in Helianthus annuus and Eucalyptus lanceolatus honey heated under different conditions during storage was made. Storage duration showed the most pronounced effect on hydroxymethylfurfural content followed by temperature and heating duration for both types of honey. Total acidity and free acids content was higher in Helianthus annuus honey than in Eucalyptus lanceolatus honey. Total acidity and free acids content increased and pH decreased in both the honey types during heating and storage. However, storage duration showed the most pronounced effect on these parameters.     

Fractional M-band dual tree complex wavelet transform for digital watermarking

In this paper, a novel digital watermarking scheme using fractional M-band dual tree complex wavelet transform (Fr-M-band-DT-CWT) is proposed. High frequency channels have wide bandwidth and low frequency channels have narrow bandwidth. These characteristics are suitable for analysing low frequency signal, but not for relatively high frequency signal. The images often contain many edges, which may cause rich middle and high frequency components in the 2-band wavelet domain. Therefore, the ordinary 2-band dual tree complex wavelet transform (DT-CWT) is not well-suited for analysing the image. So, the M-band DT-CWT with the FrFT called Fr-M-band-DT-CWT is proposed in this paper to address this problem. Further, we integrate the Fr-M-Band-DT-CWT with singular value decomposition (SVD) in order to enhance the performance. Experimental results of the proposed watermarking scheme are compared with the previously available watermarking algorithms, fractional Fourier transform (FrFT), fractional wavelet transform (FrWT). Further, the proposed watermark extraction scheme is also tested on different attacks. The results of the present investigations show that the proposed watermarking scheme is superior as compared to other existing watermarking schemes.     

IMPROVING the FUNCTIONAL and BREAD MAKING PROPERTIES of SPROUTED INDIAN WHEAT

The effect of reducing dough pH to 4.2 and addition of 2–4% gluten on rheological and pasting properties of sound and sprouted wheat flours are reported. Baking properties studied using "Medium Time Fermentation" and "Short Time Fermentation" methods revealed that an acceptable bread could be produced from even highly sprouted wheat by lowering the pH and adding 4% vital gluten to the flour, and using the "Short Time Fermentation Method".     

Influence of vitamin E supplementation on spontaneous oxidized flavour of milk in dairy buffaloes

Twenty-four Murrah buffaloes (60 days pre-partum) were divided into four equal groups (T ₁ , T ₂ , T ₃ and T ₄ ) and were supplemented with 0, 1000, 1500 and 2000 IU α-tocopheryl acetate per day up to 30 days of lactation, and half of these doses from 30 to 60 days of lactation. Milk samples collected fortnightly were analysed for vitamin E, fat, and development of oxidized flavour, with and without copper addition by a panel of judges, and chemically by the thiobarbituric acid test. Scores for oxidized flavour ranged from 0 to 10 with 0–4 as definite, 5–7 as light and 8–10 having no defect. The α-tocopherol content in milk fat (µg/g) averaged 20.55, 25.56, 29.98 and 31.38 in T ₁ , T ₂ , T ₃ and T ₄ groups, respectively. The addition of Cu in the milk significantly increased milk fat oxidation. Better stability of milk in T ₃ and T ₄ groups was observed, which might be due to a higher level of milk α-tocopherol. Addition of 1500 IU α-tocopheryl acetate in the diet of buffaloes helped in improving the oxidative stability of milk.     

Hypercube-based architecture for high speed communication systems

An implementation is presented of digital demultiplexing and demodulation algorithms for an advanced satellite communication system on a hypercube. The mapping on a hypercube provides the high speed necessary for processing hundreds of single channel per carrier/frequency division multiple access (SCPC/FDMA) voice/data channels. Data demultiplexing and demodulation are parts of the recovery of the transmitted digital data in a MODEM. A demultiplexer comprises a filter bank followed by the computation of FFT. A demodulator primarily consists of circuits to recovery carrier signal, clock frequency and data. The computation of FFT on a hypercube is well established (Hwang and Briggs 1984). Therefore, this paper analyses the filter bank and carrier and data recovery algorithms to find an efficient mapping in a multiprocessor environment connected in a hypercubic configuration. A few models to implement these algorithms on a hypercube are provided. Comparison of the speed-up achieved on a hypercube vrsus that on a sequential computer is provided for the three models.