A new merit function for custom instruction selection under an area budget constraint

This paper presents a new merit function for custom instruction selection phase of the design flow of application-specific instruction-set processors (ASIPs) in the presence of an area budget constraint. In contrast to nearly all of the previously proposed approaches where ratio of the ASIP speed to layout area is used as a merit function to select the candidate custom instructions (CIs), we show that a merit function based on normalized cycle saving and area function can result in better CI selections in terms of the achievable speedup under a given area budget for both greedy and branch-and-bound techniques. The efficacy of the proposed approach is assessed by comparing the results of using the proposed and conventional merit functions for different benchmarks. The comparison points toward an average (maximum) speed enhancement of 3.65 % (27.4 %) for the proposed merit function compared to the conventional merit functions.     

Low-power sequential circuit design using T flip-flops

This paper presents a novel circuit design technique to reduce the power dissipation in sequential circuits by using T flip-flops. The unwanted triggering action of the master clock to flip-flops can be isolated during T = 0. An example design of a decimal counter demonstrates the large power saving and improved performance of the resulting circuit.     

Interaction between inclined pile groups subjected to harmonic vibrations

Vertical and inclined piles are used in seismic areas where they could be subjected to oblique harmonic vibration loads. The effect of closely spaced battered piles on the pile–soil–pile interaction has not yet been fully recognized. A simple analytical method, based on the elasto-dynamic theory by Novak and his associates, is used in the present study to characterize vertical and inclined isolated cylindrical piles subjected to inclined harmonic vibrations. The free field movement of the ground in the vicinity of the piles is determined using an approximate approach based on the interference of the cylindrical wave field originating along each pile shaft and spreading radially outward. In calculating the interaction factor between two battered piles, an analysis has been carried out to demonstrate the effect of the presence of a neighboring pile (receiver) while the first pile (source) is loaded. In this situation, it has been found that the movement of the source pile head is decreased when a receiver pile is present. Also, the effects of the pile–pile distance, the group geometry, the length of the piles, and the inclined angle for each or all of the piles have been studied and the corresponding results will be presented.     

Parameter estimation and interval type-2 fuzzy sliding mode control of a z-axis MEMS gyroscope

This paper reports a hybrid intelligent controller for application in single axis MEMS vibratory gyroscopes. First, unknown parameters of a micro gyroscope including unknown time varying angular velocity are estimated online via normalized continuous time least mean squares algorithm. Then, an additional interval type-2 fuzzy sliding mode control is incorporated in order to match the resonant frequencies and to compensate for undesired mechanical couplings. The main advantage of this control strategy is its robustness to parameters uncertainty, external disturbance and measurement noise. Consistent estimation of parameters is guaranteed and stability of the closed-loop system is proved via the Lyapunov stability theorem. Finally, numerical simulation is done in order to validate the effectiveness of the proposed method, both for a constant and time-varying angular rate.     

Characterization of four different lignins as a first step toward the identification of suitable end‐use applications

To determine the most appropriate use of lignin, surface, structural, and thermal characteristics of lignin was investigated in this work. It was observed that kraft lignin (KL), the lignin of prehydrolysis liquor (LPHL), lignosulfonate of NSSC process (LSL), and lignosulfonates (LSs) of sulfite pulping process had 0.67, 0.25, 0.90, and 1.52–2.25 meq/g anionic charge density, and 6.3, 2.1, 10.1, and 8.8–10.1 nm hydrodynamic diameter, respectively. These results suggested that LSL and LSs could be used more effectively than other lignin as filler modifiers, flocculants, and dispersants. The combustion studies of the lignin samples suggested that KL and LPHL combusted more efficiently than other samples, as they had high heating (calorific) values of 27.02 and 19.2 MJ/kg, the apparent activation energy of 126.64 and 99.14 kJ/mol based on Flynn–Wall–Ozawa method and 122.16 and 94.73 kJ/mol based on Kissinger–Akahira–Sunose and no ash, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42336.     

Power-optimal encoding for a DRAM address bus

This paper presents an irredundant encoding technique to minimize the switching activity on a multiplexed dynamic RAM (DRAM) address bus. The DRAM switching activity can be classified either as external (between two consecutive addresses) or internal (between the row and column addresses of the same address). For external switching activity in a sequential access pattern, we present a power-optimal encoding, named Pyramid code. Extensions of the basic code address different types of DRAM devices. The proposed codes reduce power dissipation on the memory bus by a factor of two or more     

Evolutionary based multi-criteria optimization of an integrated energy system with SOFC,gas turbine,and hydrogen production via electrolysis

The aim of this study is to exploit the waste heat of a biomass-based solid oxide fuel cell (SOFC)–model (a)–in a gas turbine (GT) to enhance the power generation/exergy efficiency (model (b)). Moreover, surplus power which is generated by the GT is transferred to a proton exchange membrane electrolyzer (PEME) for hydrogen production (model (c)). Parametric study is performed to investigate the influence of the effective parameters on performance and economic indicators. Eventually, considering exergy efficiency and total product cost as the objective functions, the proposed models are optimized by multi-objective optimization method based on genetic algorithm. Accordingly, the optimum solution points are gathered as Pareto frontiers and subsequently favorable solution points are ascertained from exergy/economic standpoints. Results of parametric study indicate that model (b) is the best model as it has higher exergy efficiency and lower total product cost. Moreover, model (c) may be a more suitable model compared to the model (a) because of higher exergy efficiency and capability of hydrogen production. The results further show that, at the best final solution point, the exergy efficiency and total product cost of the model (b) would be 33.22% and 19.01 $/GJ, respectively. Corresponding values of exergy efficiency and total product cost of the model (c) are 32.3% and 20.1 $/GJ. Moreover, the rate of hydrogen production of the model (c) is 8.393 kg/day, at the best solution point. Overall, the integration methods are promising techniques for increasing exergy efficiency, reducing total product cost and also for hydrogen production.