Pragmatic integrated scheduling for clustered VLIW architectures

Clustered architecture processors are preferred for embedded systems because centralized register file architectures scale poorly in terms of clock rate, chip area, and power consumption. Scheduling for clustered architectures involves spatial concerns (where to schedule) as well as temporal concerns (when to schedule). Various clustered VLIW configurations, connectivity types, and inter‐cluster communication models present different performance trade‐offs to a scheduler. The scheduler is responsible for resolving the conflicting requirements of exploiting the parallelism offered by the hardware and limiting the communication among clusters to achieve better performance. In this paper, we describe our experience with developing a pragmatic scheme and also a generic graph‐matching‐based framework for cluster scheduling based on a generic and realistic clustered machine model. The proposed scheme effectively utilizes the exact knowledge of available communication slots, functional units, and load on different clusters as well as future resource and communication requirements known only at schedule time. The proposed graph‐matching‐based framework for cluster scheduling resolves the phase‐ordering and fixed‐ordering problem associated with earlier schemes for scheduling clustered VLIW architectures. The experimental evaluation in the context of a state‐of‐art commercial clustered architecture (using real‐world benchmark programs) reveals a significant performance improvement over the earlier proposals, which were mostly evaluated using compiled simulation of hypothetical clustered architectures. Our results clearly highlight the importance of considering the peculiarities of commercial clustered architectures and the hard‐nosed performance measurement. Copyright © 2007 John Wiley & Sons, Ltd.     

Digital Signal Processing of 400 Gbps CO-QPSK-WDM System Over Optical Wireless Channel for Carrier Phase Estimation

High bandwidth, low cost and small size has made Inter satellite optical wireless communication a promising and advance technology with an alternative to current microwave satellite systems. In this paper, advantages of coherent-detection quadrature phase shift keying (CO-QPSK) with DSP are investigated for the mitigation of non-linear effects. The technique of carrier phase estimation has been used to prolong the transmission range to several thousand kilometers. Further, 400 Gbps WDM-QPSK system has been analyzed for different distances with 30 dB transmitting power and 11 dB LO power. At last, system has been investigated at narrow channel spacing of 50 GHz and a brief comparison has been made with system having channel spacing of 100 GHz.     

Estimation of stochastic environment force for master–slave robotic system

The aim of this work is to obtain the maximum likelihood estimate (MLE) of controller-gain parameters \(\widehat{K} \) of the slave robot to determine the stochastic environment force. This is accomplished by measuring the joint positions of master and slave for a known master torque using stochastic difference equation. Here, the environmental force is modelled as a zero-mean white Gaussian random process. Therefore, the joint probability distribution function (pdf) of the slave angle over a given time duration can be computed as a function of the parameters ‘K’. This pdf is maximized with respect to ‘K’ to obtain the MLE of controller-gain parameters. Subsequently, convergence analysis of error in the estimates is performed. Also, an expression of the Cramer–Rao lower bound (CRLB) is derived to measure accuracy of the estimation. Comparison of CRLB with variance of MLE supports that our estimates are asymptotically efficient. The estimation performance is validated analytically and through simulations carried out on a two-link master–slave robotic system.     

Thermal and optical bleaching of radiation effects in silver activated metaphosphate glass-its use in U.V. dosimetry

The rapid system developed by Huppert et al. (1975) for the identification of yeasts based on assimilation and fermentation patterns and on germ tube and pseudohyphal production was evaluated in a comparative study with conventional procedures. The 95 test cultures were members of the genera Candida, Cryptococcus, Rhodotorula, Saccharomyces, Torulopsis, and Trichosporon. The study revealed that approximately 94% of the isolates were correctly identified by the rapid method in comparison with the standard method. With the rapid method identification was accomplished in 72h, and with the conventional procedures identification was completed in 2 weeks. Although it was difficult with some isolates to obtain definitive speciation by the rapid method, this method promises to be especially useful in clinical laboratories for the identification of yeasts of medical importance. Modifications were made in the procedure of Huppert et al. (1975) to improve the reading of reactions. Commercial media and a disk dispenser to make the method more useful were also investigated.     

Histomorphological and histochemical studies on systemic and pulmonary arteries of goat with advancing age. I. Occurrence of physiological intimal cushions in different arteries of goat

Thirty three goats, ranging from twenty days to over five years, were included in present investigation which revealed calcification of the different layers of seventeen different collateral arterial branches as well as various aortic segments. The initial appearance of calcium deposition and its progression with advancing age in goats was noted. The calcium deposition in the elastic elements, smooth muscle cells of tunica media, and constituents of tunica adventitia was observed and discussed in light of the available literature in domestic animals.     

COMBUSTION PERFORMANCE RELATED PROPERTIES OF AVIATION TURBINE FUELS

In recent years the hydrogen content of Aviation Fuels has generated considerable interest. Various investigators have suggested correlation of hydrogen content with combustion related properties of aviation turbine fuel (ATF). A suitable threshold value of hydrogen content 13.8 %wt is being considered as a waiver of Specification sueh as specific energy, aniline gravity product, smoke point, aromatic content, naphthalenes and luminometer number.

In the present paper relationship between the Hydrogen content and. combustion related properties have been examined and improved correlations of hydrogen content with several combustion related properties have been developed by incorporating a characterizationfactor in the equations. The supporting threshold value of a hydrogen content of 13.8 %wt is verified with 25 data points for waiving of combustion properties such as specific energy, aniline gravity product, smoke point and aromatic content from aviation turbine fuel.     

Preparation,temperature and composition dependence of some physical and electrical properties of mixtures within the NiO-Mn3O4 system

The NiO-Mn₃O₄ mixtures using cryochemically prepared powders have been made. Resitivity of the mixtures in the system with Ni_1−x Mn_2+x O₄ has been measured as a function of temperature and composition. Bulk densities, temperature coefficient of resistance, activation energy, bias voltage and time constant have also been determined. A fairly wide range of composition exists in the system suitable for thermistor application.     

Resin-tooth interfacial morphology and sealing ability of one-step self-etch adhesives: microleakage and SEM study

OBJECTIVES: To compare microleakage of three self‐etch adhesives and to analyze enamel surface morphology and interfacial morphology of resin–enamel and resin–dentin interface under scanning electron microscope (SEM). EXPERIMENTAL DESIGN: Study was conducted in 65 extracted human premolars. Class V cavities were prepared in 45 teeth and assigned to three groups (n = 15) according to three self‐etch adhesives (OptiBond All‐in‐One, iBond, and Adper Prompt L‐Pop). After restoration, 10 samples from each group were used to assess microleakage at enamel and dentin margin. Five samples from each group were used for analysis of interfacial morphology at resin–enamel and resin–dentin interface under SEM. Remaining 20 teeth were used to prepare flat enamel buccal surfaces to analyze the difference in surface morphology after treatment with three adhesives (n = 5 each) and 36% phosphoric acid treatment (n = 5). PRINCIPAL OBSERVATIONS: At enamel margin, Prompt L‐Pop depicted least leakage of all the three adhesives and also showed best interfacial adaptation under SEM. At dentin margin, OptiBond All‐in‐One showed significant less leakage than iBond and Prompt L‐Pop. On flat enamel surface, phosphoric acid produced the most retentive etching pattern when compared with the three adhesives. CONCLUSION: Prompt L‐Pop showed the best bonding effectiveness in enamel, whereas OptiBond All‐in‐One performed significantly better in dentin. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.