International Journal of Engineering
Volume:20 Issue: 3, Oct 2007

In this paper the design of a new high-speed current mode BiCMOS logic circuits isproposed. By altering the threshold detector circuit of the conventional current mode logic circuitsand applying the multiple value logic (MVL) approach the number of transistors in basic logicoperators are significantly reduced and hence a reduction of chip area and power dissipation as wellas an increase in speed is achieved. Simulation with HSpice using BSIM 3V3 model and experimental65nm BiCMOS technology were carried out for speed, and power consumption considerations atdifferent supply voltage levels. Finally the performance of the proposed circuit is compared to an 8 bitvoltage mode adder.

In this paper, using the three-phase induction motor fifth order model in a stationary twoaxis reference frame with stator current and rotor flux as state variables, a conventional backsteppingcontroller is first designed for speed and rotor flux control of an induction motor drive. Then in orderto make the control system stable and robust against all electromechanical parameter uncertainties aswell as to the unknown load torque disturbance, the backstepping control is combined with artificialneural networks in order to design a robust nonlinear controller. It will be shown that the compositecontroller is capable of compensating the parameters variations and rejecting the external load torquedisturbance. The overall system stability is proved by the Lyapunov theory. It is also shown that themethod of artificial neural network training, guarantees the boundedness of errors and artificial neuralnetwork weights. Furthermore, in order to make the drive system free from flux sensor, a slidingmoderotor flux observer is employed that is also robust to all electrical parameter uncertainties andvariations. Finally, the validity and effectiveness of the proposed controller is verified by computersimulation.

Statistical process control methods for monitoring processes with univariate ormultivariate measurements are used widely when the quality variables fit to known probabilitydistributions. Some processes, however, are better characterized by a profile or a function of qualityvariables. For each profile, it is assumed that a collection of data on the response variable along withthe values of the corresponding quality variables is measured. While the linear function is thesimplest, it occurs frequently that many of the nonlinear functions may be transferred to linearfunctions easily. This paper proposes a control chart based on the generalized linear test (GLT) tomonitor coefficients of the linear profiles and an R-chart to monitor the error variance, thecombination of which is called GLT/R chart. While fixed values of the explanatory variables arecornerstones in other control charts proposed to monitor profiles, in GLT/R chart, it is not a necessarycondition. In order to illustrate the robustness of the GLT/R chart a simulation study has been done intwo different cases, i.e. fixed and non-fixed values of the explanatory variables. Then, the resultsobtained from GLT/R charts are compared to the ones from a multivariate T2 and ExponentiallyWeighted Moving Average/R (EWMA/R) control charts.

This paper deals with the transient analysis of K-out-of-N: G system consisting of Noperatingmachines. To improve system reliability, Y cold standby and S warm standbys spares areprovided to replace the failed machines. The machines are assumed to fail in multiple modes. At leastK-out-of-N machines for smooth functioning of the system. Reliability and mean time to failure areestablished in terms of transient probabilities.

Location decision is an integral part of organizational strategies involving many factorsthat may be conflicting in nature. This paper presents a holistic approach of the multi-criteria decisionmaking (MCDM) methodology to select the optimal location(s), which fits best for both investors andmanagers. A case study is also provided to illustrate the application of the proposed holistic approach.Finally, a comparison with the previous work is made and the informational efficacy of the proposedmodel is also discussed.

Due date assignment for customer orders has been studied in various productionenvironments using different modeling approaches. In this paper the researchers consider aproduction system in which the orders of several customers are produced in a single batch because ofthe economy of scale. If a batch is completed before receiving customer orders, inventory carryingcost is incurred but if it is completed after receiving customer orders, shortage cost is incurred andfinally if the order is delivered after its due date, tardiness cost is charged. The problem is to decideon batch size, due date of batch (imposed on supply process) and lead time (to be quoted to the nextcoming customers) so that relevant costs are minimized. The objective function is to minimize totalcost of supply, inventory carrying, shortage and tardiness. Production flow times are probabilisticwhich follow a probability distribution. The proposed model is solved using real-coded geneticalgorithms and numerical results are presented. This work was motivated by a heavy equipmentproduction system which has some products with relatively low demand rates, high prices and longsupply lead times.

In this paper, the effects of two different Particle Size Distributions (PSD) on packingbehavior of ideal rigid spherical nanoparticles using a novel packing model based on parallelalgorithms have been reported. A mersenne twister algorithm was used to generate pseudorandomnumbers for the particles initial coordinates. Also, for this purpose a nanosized tetragonal confinedcontainer with a square floor (300 * 300 nm) were used in this work. The Andreasen and the LognormalPSDs were chosen to investigate the packing behavior in a 3D bounded region. The effects ofparticle numbers on packing behavior of these two PSDs have been investigated. Also thereproducibility and the distribution of packing factor of these PSDs were compared.

For laterally complex media, it may be more suitable to take a different orientation of thedisplacement vector of Shear-waves. This may change the sign of several imaginary reflections andconversion coefficients to be used in reservoir characterization and AVO (Amplitude Versus Offset)analysis or modeling. In this new convention the positive direction of the displacement vector ofreflected Shear-waves is chosen to the left of ray tangent (in the direction of wave propagation).Therefore, the definition of the displacement vector of shear-waves can be used properly even forvery complicated media. Finally the shear-wave dynamic behavior of a reservoir zone can beillustrated for laterally varying structures in terms of the amplitude variation and phase behavior usingthis new orientation.