Influence of carcass weight on instrumental and sensory lamb meat quality in intensive production systems

The effects of cooking viz. pressure-cooking and broiling and storage at 4 °C for six days and -10 °C for 90 days on lipid oxidation and development of cholesterol oxidation products in mutton were studied. Results revealed that cooking of meat significantly increased the total lipids, phospholipids, cholesterol, glycolipids, free fatty acids and glycerides, but they did not change during refrigerated and frozen storage. The TBA values increased on cooking and during storage. However, the values were below the threshold level for rancidity development. The following cholesterol oxidation products were separated by thin layer chromatography cholestanetriol, 7-α-hydroxy cholesterol, 19-hydroxycholesterol, 7-ketocholesterol, cholesterol-α-epoxide, cholesterol-β-epoxide and an unidentified fraction. All these fractions except the unidentified fraction increased on cooking. On refrigerated and even on frozen storage all these fractions increased except the unidentified fraction, which showed a concomitant reduction. The changes in broiled meat were more pronounced compared to pressure-cooked meat. Results clearly indicated that even frozen storage of cooked meat did not prevent the development of cholesterol oxidation products.     

Veal colour assessment with three wavelengths

A method to derive reflectance spectra and colour coordinates of meat by measurement of reflectance at only three wavelengths, 480, 570 and 620 nm has been developed, by treating the spectra of a meat sample as a linear combination of the spectra of the three major myoglobin derivatives (reduced myoglobin, oxymyoglobin and metmyoglobin). Applied to 300 samples of Semitendinosus and Longissimus dorsi veal muscles at different times post mortem (24 h to 9 d), colour differences ΔE (?) between the derived spectra and the real ones were about 1.5 units. The total pigment content, with high correlation with the extraction method (P < 0.02), and the relative proportions of the derivatives can also be estimated.     

An 8-Bit Digitally Controlled Programmable Phase Shifter Circuit for Sinusoidal Signals with 252∘ Phase Control Range

In this paper, the synthesis, design, and implementation of a programmable phase shifter circuit for sinusoidal signals is presented. The proposed circuit, built-up herein with operational amplifiers (OPAMPs), high precision resistors and low voltage switches, consists of a digitally controlled amplitude attenuator in combination with a single-tone orthogonalizer. Experimental results agree with theoretical background: the attained phase range was 252^° in 256 steps with a median step of 0.9^°. The inaccuracy of the circuit was determined to be of 0.03 %. Contrary to other OPAMP approaches for sinusoidal signals reported in the literature and based on a first-order all-pass filter structure, the approximation suggested in this work is based on a different concept. The achieved results demonstrate the functionality of the system for the case of a sinusoidal signal with frequency of 1 kHz. Notwithstanding, the proposed architecture can be extended to operate at higher frequencies by using different building blocks with larger bandwidth. Furthermore, it can be extended as well to work out with other periodic input waveforms, like triangular shapes or square waves, with the use of an appropriate orthogonalizer.     

On Burst Length Distribution and Preemption Probabilities in OBS Networks with Burst Segmentation

Recently, preemption techniques have attracted considerable attention as a means to provide differentiated quality of service in optical burst switching (OBS) networks. This paper is focused on the analysis of preemption probabilities for bursts within the same priority class. As proposed by Vokkarane and Jue ((2003)* IEEE J Select Areas Commun 21(7): 1198–1209) an incoming burst will preempt the burst in service, within the same priority class, if the residual length of the burst in service is smaller than the incoming burst length. For a general case with wavelength conversion, the preemption probability of contending bursts with a generic service distribution, not necessarily exponential, is analyzed. First, we show that the size distribution for the preempting bursts is shifted to larger values, in comparison to the original burst size distribution. Second, we obtain an upper and lower bound for the preemption probability. Finally, the asymptotic behavior of the OBS switch is analyzed showing that preemption will always occur for a very large number of wavelengths.     

A 0.8 μm CMOS testable switched-capacitor filter for video frequency applications

This paper presents the design of a fifth-order low-pass elliptic filter that employs a parallel connection of two all-pass sections to satisfy specifications commonly used in video frequency applications. Operating with a sampling frequency of 16 MHz, the IC prototype was implemented in a standard double-poly CMOS 0.8 μm process. The experimental verification showed a passband frequency deviation smaller than 0.08 dB up to the passband edge frequency of 3.4 MHz, and an output noise power of 0.97 ${\mu {\rm V}_{\rm RMS}}/{\sqrt {Hz}}This paper presents the design of a fifth-order low-pass elliptic filter that employs a parallel connection of two all-pass sections to satisfy specifications commonly used in video frequency applications. Operating with a sampling frequency of 16 MHz, the IC prototype was implemented in a standard double-poly CMOS 0.8 μm process. The experimental verification showed a passband frequency deviation smaller than 0.08 dB up to the passband edge frequency of 3.4 MHz, and an output noise power of 0.97 , resulting in a dynamic range of 49.1 dB. The filter structure enables multiple fault detection and suits modern automated testing configurations to allow accurate estimation of the actually implemented transfer function parameters, an issue of increasing importance in VLSI circuit design. The relative area required for testing the fifth-order filter is only 8% of the total filter area, and decreases as the filter order increases. Jorge Morales Ca?ive was born in Cienfuegos, Cuba, in 1963. He received the B.Sc. and M.Sc. degrees from the Technical University of San Petersburg, Russia, in 1986 and 1988, respectively, and the D.Sc. degree from the Federal University of Rio de Janeiro, Brazil, in 1991, all in electrical engineering. From 1988 to 1994, he worked at CEADEN, in Havana, Cuba, on the development of nuclear equipments. From 1994 to 1997, he worked at INOR, in Havana, Cuba, on the research and development of acquisition systems and image processing for nuclear medicine. His research interests are in the areas of analog and digital signal processing. Antonio Petraglia (S’89-M’91-SM’99) received the Engineer and M.Sc. degrees from the Federal University of Rio de Janeiro (UFRJ), Brazil, in 1977 and 1982, respectively, and the Ph.D. degree from the University of California, Santa Barbara (UCSB), in 1991, all in electrical engineering. In 1979, he joined the Faculty of UFRJ as an Associate Professor of electrical engineering, where he served as a Co-Chair in the Department of Electronic Engineering from 1982 to 1984. During the second semester of 1991, he was a post-Doctoral researcher with the Department of Electrical and Computer Engineering at UCSB. Since 1992 he has been on the faculty of the Program for Post-Graduate Engineering at UFRJ, where in 1997 he established the Laboratory for the Processing of Analog and Digital Signals. From March 2001 through March 2002 he was a Visiting Scholar with the Electrical Engineering Department at the University of California, Los Angeles. He has been involved in teaching and research activities in the areas of analog and digital signal processing, and in mixed analog-digital integrated circuit design. He is a distinguished member of the Brazilian Millenium Group in Nanoelectronics and Microelectronics in 2006-2008. Dr. Petraglia served as an Associate Editor for the IEEE Transactions on Circuits and Systems-II: Analog and Digital Signal Processing in 2002–2003 Mariane Rembold Petraglia (M’97) received the B.Sc. degree in electronic engineering from the Federal University of Rio de Janeiro, Brazil, in 1985, and the M.Sc. and Ph.D. degrees in electrical engineering from the University of California, Santa Barbara, in 1988 and 1991, respectively. From 1992 to 1993, she was with the Department of Electrical Engineering, Catholic University of Rio de Janeiro, Brazil. Since 1993, she has been with the Department of Electronic Engineering and with the Program of Electrical Engineering, COPPE, at the Federal University of Rio de Janeiro, where she is presently an Associate Professor. From March 2001 to February 2002, she was a Visiting Researcher with the Adaptive Systems Laboratory, at the University of California, Los Angeles. Her research interests are in adaptive signal processing, multirate systems, and image processing. Dr. Petraglia is a member of Tau Beta Pi, and a distinguished member of the Brazilian Millenium Group in Nanoelectronics and Microelectronics in 2006–2008. She is serving as an Associate Editor for the IEEE Transactions on Signal Processing since Nov. 2004.     

Low-cost group rekeying for unattended wireless sensor networks

Wireless sensor networks (WSNs) are made up of large groups of nodes that perform distributed monitoring services. Since sensor measurements are often sensitive data acquired in hostile environments, securing WSN becomes mandatory. However, WSNs consists of low-end devices and frequently preclude the presence of a centralized security manager. Therefore, achieving security is even more challenging. State-of-the-art proposals rely on: (1) attended and centralized security systems; or (2) establishing initial keys without taking into account how to efficiently manage rekeying. In this paper we present a scalable group key management proposal for unattended WSNs that is designed to reduce the rekeying cost when the group membership changes.     

Proportional Plus Integral Control for Set-Point Regulation of a Class of Nonlinear RLC Circuits

In this paper we identify graph-theoretic conditions which allow us to write a nonlinear RLC circuit as port-Hamiltonian with constant input matrices. We show that under additional monotonicity conditions on the network’s components, the circuit enjoys the property of relative passivity, an extended notion of classical passivity. The property of relative passivity is then used to build simple, yet robust and globally stable, proportional plus integral controllers. This work was partially supported by CONACyT, México.     

Euclidean Geometry LDPC-VBLAST System Design and Performance Evaluation

Among popular multi-transmit and multi-receive antennas techniques, the VBLAST (Vertical Bell Laboratories Layered Space-Time) architecture has been shown to be a good solution for wireless communications applications that require the transmission of data at high rates. Recently, the application of efficient error correction coding schemes such as low density parity-check (LDPC) codes to systems with multi-transmit and multi-receive antennas has shown to significantly improve bit error rate performance. Although irregular LDPC codes with non-structure are quite popular due to the ease of constructing the parity check matrices and their very good error rate performance, the complexity of the encoder is high. Simple implementation of both encoder and decoder can be an asset in wireless communications applications. In this paper, we study the application of Euclidean geometry LDPC codes to the VBLAST system. We assess system performance using different code parameters and different numbers of antennas via Monte-Carlo simulation and show that the combination of Euclidean geometry LDPC codes and VBLAST can significantly improve bit error rate performance. We also show that interleaving data is necessary to improve performance of LDPC codes when a higher number of antennas is, used in order to mitigate the effect of error propagation. The simplicity of the implementation of both encoder and decoder makes Euclidean geometry LDPC codes with VBLAST system attractive and suitable for practical applications.     

Compact charge and capacitance modeling of undoped ultra-thin body (UTB) SOI MOSFETs

We present an analytic, explicit and continuous charge model for a long-channel UTB (ultra-thin body) SOI (silicon-on-insulator) MOSFET, from which analytical expressions of the total capacitances are obtained. Our model is valid from below to well above threshold, without suffering from discontinuities between the regimes. It is based on a unified charge control model derived from Poisson’s equation. The drain-current, charge and capacitances expressions result in continuous explicit functions of the applied bias.The calculated capacitance characteristics are validated by 2D numerical simulations showing a very good agreement for different silicon film thicknesses.